The advocates say the new voters could make a difference in the presidential race, where most of the Republican field has tacked to the right in word and policy, and in key Senate races in Illinois and Florida, where Republicans will be reaching to hang on to critical seats.

With nearly 9 million legal immigrants already eligible to become citizens, the 1 million goal is not far-fetched. The activists say they are counting on energizing another 2 million Hispanic citizens who have turned 18 since 2012 and who they believe will turn out to vote to defend fellow Dreamers, or young illegal immigrants, against Republican calls for their deportation.

“This is a huge amount of latent power,” said Joshua Hoyt, executive director of the National Partnership for New Americans, the group he and other leaders announced Thursday at the National Press Club.

The effort is funded in part by the Open Society Foundation, the project of liberal billionaire George Soros.